package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import jodd.util.StringUtil;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.BLOG_LIKED_KEY;
import static com.hmdp.utils.RedisConstants.FEED_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Resource
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IFollowService followService;

    @Override
    public Result queryBlogById(Long id) {
        //1、查询blog
        Blog blog = getById(id);
        if (blog == null){
            return Result.fail("笔记不存在！");
        }
        //2、查询blog有关用户
        queryBlogUSer(blog);
        //3、查询blog是否被点赞
        isBlogLike(blog);
        return Result.ok(blog);
    }

    private void isBlogLike(Blog blog) {
        //1、获取当前登录用户
        UserDTO user = UserHolder.getUser();
        if (user == null){
            // 用户未登录
            return;
        }
        Long userID = UserHolder.getUser().getId();
        //2、判断当前登录用户是否点赞
        String key = BLOG_LIKED_KEY + blog.getId();

        Double score = stringRedisTemplate.opsForZSet().score(key, userID.toString());

        blog.setIsLike(score != null);


    }


    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach(blog ->{
            this.queryBlogUSer(blog);
            this.isBlogLike(blog);
        });
        return Result.ok(records);
    }

    @Override
    public Result likeBolg(Long id) {
        //1、获取当前登录用户
        Long userID = UserHolder.getUser().getId();
        //2、判断当前登录用户是否点赞
        String key = BLOG_LIKED_KEY + id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userID.toString());

        if(score == null){
            //3、如果未点赞可以点赞
            //3.1数据库点赞数 +1
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //3.2 保存用户信息到Redis的set集合中 zadd key key value score
            if(isSuccess){
                stringRedisTemplate.opsForZSet().add(key,userID.toString(),System.currentTimeMillis());
            }
        }else{
            //4、已点赞，取消点赞
            //4、数据库点赞数 -1
            boolean isSuccess = update().setSql("liked = liked - 1").eq("id", id).update();
            //4.2 把用户从redis中的set集合中取消
            if(isSuccess){
                stringRedisTemplate.opsForZSet().remove(key,userID.toString());
            }
        }
        return Result.ok();

    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key = BLOG_LIKED_KEY + id;
        //1、查询top5的点赞用户
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if (top5 == null || top5.isEmpty()){
            return Result.ok();
        }
        //2、解析启用的用户id
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        String idStr = StrUtil.join(",", ids);
        //3、根据id查询用户 where in(5,1) order by field(id,5,1)
        List<Object> userDTOs = userService.query().in("id",ids).last("order by field(id," + idStr + ")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        //4、返回
        return Result.ok(userDTOs);
    }

    @Override
    public Result saveBlog(Blog blog) {
        // 1、获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        // 2、保存探店博文
        boolean isSuccess = save(blog);
        if(!isSuccess){
            return Result.fail("新增笔记失败");
        }
        //3、查询笔记作者的所有粉丝
        List<Follow> follows = followService.query().eq("follow_user_id", user.getId()).list();
        //4、推送笔记id给所有粉丝
        for (Follow follow: follows){
            //4.1、获取粉丝id
            Long userID = follow.getUserId();
            //4.2、推送
            String key = "feed:" + userID;
            stringRedisTemplate.opsForZSet().add(key,blog.getId().toString(),System.currentTimeMillis());
        }
        // 5、返回id
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        //1、获取当前用户
        Long userId = UserHolder.getUser().getId();
        //2、查询收件箱 zrevrangebyscore key  Max Min limit offset count
        String key = FEED_KEY + userId;
        Set<ZSetOperations.TypedTuple<String>> typeTuple = stringRedisTemplate.opsForZSet().reverseRangeByScoreWithScores(key, 0, max, offset, 2);
        if (typeTuple == null || typeTuple.isEmpty()){
            return Result.ok();
        }
        //3、解析数据：blogId、minTime（时间戳）.offset
        List<Long> ids = new ArrayList<>(typeTuple.size());
        Long minTime = 0L;
        int os = 1;
        for (ZSetOperations.TypedTuple<String> type : typeTuple) {
            //获取id
            ids.add(Long.valueOf(type.getValue()));
            //获取分数
            long time = type.getScore().longValue();
            if (time == minTime){
                os++;
            }else {
                minTime =time;
                os = 1;
            }
        }
        //4、根据id查询blog
        String idStr = StrUtil.join(",",ids);
        List<Blog> blogs = query().in("id", ids).last("order by field(id," + idStr + ")").list();
        for (Blog blog : blogs) {
            //查询blog有关用户
            queryBlogUSer(blog);
            //查询blog是否被点赞
            isBlogLike(blog);
        }
        //5、封装并放回
        ScrollResult scrollResult = new ScrollResult();
        scrollResult.setList(blogs);
        scrollResult.setMinTime(minTime);
        scrollResult.setOffset(os);
        return Result.ok(scrollResult);
    }

    private void queryBlogUSer(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }


}
